Apparatus for selectively examining radioactive samples

ABSTRACT

An apparatus having a series of movable trays for holding a plurality of radioactive samples, and for transporting each tray and each sample carried thereon to a shielded detection unit for examination.

United States Patent Hof et al.

[54] APPARATUS FOR SELECTIVELY EXAMINING RADIOACTIVE SAMPLES [72]Inventors: Jan Sjouke lloi, Waalre; Gerardus Otten,

Emmasingel, Eindhoven, both of Netherlands [73] Assignee: U.S. PhilipsCorporation, New York, N.Y.

[22] Filed: Sept. 3, 1968 21 Appl. No.2 756,998

[30] Foreign Application Priority Data Sept. 2, 1967 Netherlands..67l2087 [52] U.S. Cl. ..250/106, 214/164, 250/71.5 [51] ..GOlt 7/02,G01t7/08 [58] Field of Search ..250/7i.5, 106 SC; 214/] 1, 16.4

[ 51 Apr. 4, 1972 [56] References Cited UNITED STATES PATENTS 2,932,2634/l960 Leuthauser ..2 l 4/1 6.4 3,257,561 6/1966 Packard et al.3,422,268 l/l969 Meinig ..250/106 SC Primary Examiner-Archie R. BorcheltAttorney-F rank R. Trifari [5 7] ABSTRACT An apparatus having a seriesof movable trays for holding a plurality of radioactive samples,'and fortransporting each tray and each sample carried thereon to a shieldeddetection unit for examination.

6 Claims, 4 Drawing Figures PATENTEUAPR 41922 SHEET 1 BF 3 1N VENTOR? BYJAN 3- H01:

GERAR us or'rgn M E AGENT PATENTEDAPR 4|972 3,654,472

SHEET 2 [IF 3 INVENTOR5 Y JAN 3. HOF

GERARDU 0115 N GENT PATENTEUAPR 4 I972 3, 654,472

sum 3 or 3 INVENTORP BY JAN 5. HOF

GERARDUS OTTE v AGENT APPARATUS FOR SELECTIVELY EXAMINING RADIOACTIVESAMPLES The invention relates to a composition changer for examiningradioactive compositions which are present in containers and may bemixed with a scintillator liquid. The changer is provided with aplurality of parallel arranged holders which are each designed to hold agroup of containers containing the compositions to be examined, means toremove a container from the holder, to bring said container in ashielded detector chamber, to examine it, and to remove it again fromsaid chamber.

In a known composition changer a group of containers is accomodated inapertures along a circular periphery of a round disc. This disc forms amagazine for the containers which may be designed as small bottles. Inthis changer a plurality of said discs is fixedly arranged above oneanother and every time one disc is completely moved out of the stack andconveyed up to exactly above a detector chamber; by rotating the discabout its center a different container is led every time above thechamber and introduced therein. After examination the container isplaced again in the disc which is conveyed back to the stack.

Although the known device is suitable for a very large number ofcontainers, it has the drawback ofbeing comparatively voluminous;because the containers are only arranged along a circular periphery. Adisc having a large diameter is already required for proportionally fewcontainers. Furthermore a complicated mechanism is required for theintricate transport path leading the disc from the stack to themeasuring arrangement.

An object of the invention is to provide a changer in which thetransport path for the containers is considerably simplified andshortened and which can accommodate a great many containers in aproportionally small volume. To this end the changer according to theinvention is characterized in that the holders are oblong and are eachdesigned to accommodate the containers in one or more parallel straightrows, the holders being movable in parallel with one another, in a pathtranversely to their longitudinal dimension and closed in itself.

In the device according to the invention all containers are thus movedin parallel rows along a path closed in itself. When a desired row hasarrived in a pre-determined position in the afore-mentioned path, thedesired container is removed from the holder by means of suitablemembers and conveyed to the measuring position.

Starting from an arrangement in which each holder may be provided withpossibly a double row of containers, one embodiment of a compositionchanger has means for moving a holder preferably stepwise in itslongitudinal direction when said holder has assumed a pre-determinedposition in the path. This provides the interesting possibility toaccommodate the holders movably in gutter-like trays which are open atat least one end, said holders having a plurality of bottomlessapertures for receiving the containers and extending in a verticaldirection up to the bottoms of the trays. The containers, which are, forexample, formed as sample bottles, then fit in the bottomless aperturesof the holder which rests on the bottom of the trough-like tray inunextended position; not until the holder is slid out of the tray canthe containers be conveyed in downward direction to a measuring chamber.

For transporting holders along a path which is closed in itself, use canbe made of two chains between which the parallel movable holders aresuspended in such manner that the mutual position of the containers ismaintained during the transport of the holders along the path. The endsof each troughlike tray can then be fixed permanently to brackets whichare secured to the links of the chains. In this connection it isotherwise noted that it is known per se from US. Pat. specification No.3,302,025 to transport a large number of containers by means of aflexible belt along a measuring chamber housing a detector, pick-upmembers being utilized for removing the containers containing thecompositions to be tested from the belt path and to be conveyed to themeasuring chamber (and vice versa).

In order that the invention may be readily carried into effect it willnow be described in detail, by way of example, with reference to theaccompanying diagrammatic drawings in which:

FIG. 1 is a perspective elevational view of the changer according to theinvention,

FIG. 2 relates to transporting holders containing sample bottles to betested, along a path by means of a transport chain,

FIG. 3 is part of a vertical cross-section taken on the line llllll ofFIG. 1, and

FIG. 4 is a perspective view ofa transport tray having an extensibleholder for samples to be tested.

The composition changer of FIG. 1 has two transport chains 1 and 3 whichare synchronously moved by the same shaft 4 and between which aplurality of transport trays for sample bottles are suspended inbrackets in the manner as for an endless conveyer. FIG. 2 shows thechain 3 in part and brackets 5, 7, which have a common pivot at 9secured to the links of these chains. The brackets 5, 7 are shown as twolines in FIG. 1. Trough-like trays 19 for holding sample bottles to betested .are suspended between corresponding sets of brackets of the twochains. To this end use is made of carrier plates 11 secured to thebrackets 5, 7 which carrier plates have bent edges 13 between which thetrays 19 with their flanged edges 15 and 17 can slide.

Due to the endless arrangement, all holders remain comparativelyhorizontal. Each series of parallel arranged trays 19, which are open atone end, is furthermore designed to comprise a holder 21 ofa syntheticmaterial which can be slid out of the tray 19 in the longitudinaldirection as is shown in FIG. 4. The holder 21 is provided withbottomless apertures 23 in which containers holding the compositions tobe examined are held in place. In this example the containers aredesigned as small bottles 25 which are supported by the bottom of thetray '19 as long as the holder still completely remains in the tray.

In thelowest position of the chain path the holders 21 are successivelyslid out of the trays 19 in stepwise manner. To this end reference isalso made to FIG. 3. The holder 21 is slid out of the tray 19 in thelongitudinal direction with the aid of a lug 29 which is moved stepwisein the direction indicated by arrow 27 and co-acts with a hook-like part31 of the holder 21. In unextended position the lug 29 is located at theextreme right. The hook-like part 31 is arranged behind the lug 29 insaid extreme right position by moving the tray 19 in the directiontransversely to the plane of the drawing whereby the part 31 slides overthe lug 29. An index mechanism of conventional construction may serve tomove on the lug 29.

A detector chamber formed by lead walls 37 and accommodating detectionmeans 39, 41 is located underneath the chain conveyer. A plunger 43 canbe displaced in the direction of height in an aperture 48 of thischamber; it is driven by a shaft 45 which causes the pin 47 inserted inplunger 43 to move up and down through a suitable gear. In its highestposition the plunger 43 can receive a bottle 51 from the holder 21, andhold it between the detectors 39 and 41 in its lowest position at whichthe measurement for radioactivity takes place in conventional manner.The bushing 50 then provides for additional shielding of the light whenthe plunger 43 is in its upper position. As the plunger moves down thebushing is also taken along downwards by shoulder 52.

Furthermore there is provided a shield 55 rotatable by shaft 53 andhaving apertures the shield passes a bottle 51 in one position andcovers the space above the lowered bottle 51 in light-tight manner atone position farther. After measurement shield 55 is further rotateduntil another aperture is released in the path of the plunger, and thebottle 51 can be lifted again into the holder 21. While the upper side59 of the plunger 43 is in the broken-line position and forms atemporary base for the bottle 51, the holder 21 is displaced over adesired distance and another bottle can be lowered. When an entire rowof bottles of a holder has been handled, the lug 29 is again moved tothe extreme right and the holder 21 is thus returned to its originalposition. Subsequently the chains 1, 3 are moved slightly further sothat the second row of bottles of the same holder 21 can be slid out.

The composition changer furthermore comprises an electronic controlsection with which a desired program of operations, such astransporting, measuring, recording, can be carried out. This section canbe seen in the right part of FIG. 1 and comprises a plurality of controland measuring units placed upon one another. Since these units do notform an essential part of the present invention their description hasbeen omitted.

We claim:

1. Apparatus for retaining a plurality of sample containers ofradioactive material and transporting one at a time to a detector forexamination, comprising:

a. a frame,

b. a plurality of carriers movably disposed in spaced relationship onthe frame,

c. a plurality of holders, each (i) having a plurality of aperturesalong a longitudinal axis for retaining sample containers, and (ii)secured to and axially movable relative to one carrier,

d. a transfer assembly for maintaining the carriers and holders spacedand parallel with respect to other carriers and holders, and fortransporting the carriers and holders along a continuous generallyelongated path having closely adjacent sides, with the carriers andholders on said sides of the path being correspondingly adjacent, thepath also defining a discharge area to which each holder is transported,

. a shielded detector including an aperture for receiving one samplecontainer at a time, and

f. the transfer assembly further comprising means cooperating with eachholder at the discharge area, for selectively moving each holder axiallywith respect to its carrier and a selected container to a dischargepoint for transport from the holder to said detector for examinationthereof, and returning the container to its holder.

2. Apparatus according to claim 1 wherein said transfer assembly moveseach holder axially in steps for selectively locating each aperture ofthe holder closely adjacent the discharge area, before each container istransported from each holder to the detector.

3. Apparatus according to claim 1 wherein said transfer assembly furthercomprising a tray secured in an upright position to each carrier, witheach holder supported by the bottom of a tray and each holder aperturebeing bottomless and oriented vertically, whereby axial movement of aholder relative to the corresponding tray permits containers to be movedat the discharge area vertically downward to the detector.

4. Apparatus according to claim 3 wherein said transfer assembly furthercomprises flexible guide means disposed along said path and motor meansdriving the assembly for transporting the carriers and holders.

5. Apparatus according to claim 1 wherein said frame further includes aclosable duct between the discharge area and the detector, and saidtransfer assembly opens the duct before transporting each container viathe duct to the detector, and subsequently closes the duct.

6. Apparatus according to claim 2 wherein the transfer assembly furthercomprises a pair of chain links spaced apart and supporting saidcarriers therebetween.

1. Apparatus for retaining a plurality of sample containers ofradioactive material and transporting one at a time to a detector forexamination, comprising: a. a frame, b. a plurality of carriers movablydisposed in spaced relationship on the frame, c. a plurality of holders,each (i) having a plurality of apertures along a longitudinal axis forretaining sample containers, and (ii) secured to and axially movablerelative to one carrier, d. a transfer assembly for maintaining thecarriers and holders spaced and parallel with respect to other carriersand holders, and for transporting the carriers and holders along acontinuous generally elongated path having closely adjacent sides, withthe carriers and holders on said sides of the path being correspondinglyadjacent, the path also defining a discharge area to which each holderis transported, e. a shielded detector including an aperture forreceiving one sample container at a time, and f. the transfer assemblyfurther comprising means cooperating with each holder at the dischargearea, for selectively moving each holder axially with respect to itscarrier and a selected container to a discharge point for transport fromthe holder to said detector for examination thereof, and returning thecontainer to its holder.
 2. Apparatus according to claim 1 wherein saidtransfer assembly moves each holder axially in steps for selectivelylocating each aperture of the holder closely adjacent the dischargearea, before each container is transported from each holder to thedetector.
 3. Apparatus according to claim 1 wherein said transferassembly further comprising a tray secured in an upright position toeach carrier, with each holder supported by the bottom of a tray andeach holder aperture being bottomless and oriented vertically, wherebyaxial movement of a holder relative to the corresponding tray permitscontainers to be moved at the discharge area vertically downward to thedetector.
 4. Apparatus according to claim 3 wherein said transferassembly further comprises flexible guide means disposed along said pathand motor means driving the assembly for transporting the carriers andholders.
 5. Apparatus accordIng to claim 1 wherein said frame furtherincludes a closable duct between the discharge area and the detector,and said transfer assembly opens the duct before transporting eachcontainer via the duct to the detector, and subsequently closes theduct.
 6. Apparatus according to claim 2 wherein the transfer assemblyfurther comprises a pair of chain links spaced apart and supporting saidcarriers therebetween.